1. Field of Invention
The present invention relates to a speaker module design. More particularly, the present invention relates to a speaker module for a hand-held electronic device.
2. Description of Related Art
In this information age, our reliance on electronic products can be seen everywhere. For example, we use mobile phones, computers and audio-visual products every day. As manufacturing techniques for electronic devices continue to advance, more personalized and multi-functional electronic products are available in the market. With big leaps in the communication industry, the mobile phone is becoming increasingly common in our society.
Starting out bulky and heavy, the first generation of mobile phones has transformed into slim and lightweight palm-top phones. Yet, most manufacturers are still researching methods to reduce the weight and size of existing mobile phones for greater portability. In the meantime, manufacturers are also trying hard to expand the function of each mobile phone and reduce as much as possible any harmful effects due to electromagnetic radiation, however small they actually are. However, reducing the size of an existing mobile phone involves a close matching of all the elements within the mobile phone including the location and size of a speaker box for housing a speaker unit. In fact, quality of sound emitted from the phone largely depends on the size of the speaker box. In general, a larger speaker box can obtain a better sound quality. Nevertheless, due to the miniaturization trend of the hand-held electronic device, a speaker box has a large size is no longer practical. Hence, how to devise a speaker box that can improve the sound quality while does not need to increase in size is an important topic for manufacturers of hand-held electronic devices.
FIG. 1 is a cross-sectional view showing major components and an internal structure of a conventional speaker module 100 inside a mobile phone 10. As shown in FIG. 1, the conventional speaker module 100 is installed inside a casing 12 of the mobile phone 10. The speaker module 100 mainly includes a speaker unit 110 and a speaker box 120. The speaker box 120 houses the speaker unit 110. Aside from serving as a sound-producing loudspeaker, the speaker unit 110 also functions as a buzzer with specialized response at high frequency. Furthermore, the speaker unit 110 can also function as a receiver. Thus, the speaker unit 110 in the mobile phone 10 serves three major functions altogether. In addition, the wall at one end of the speaker box 120 has an aperture 120a that accommodates the speaker unit 110. A printed circuit board 14 within the mobile phone 10 also has a hole 14a for fittingly receiving the entire speaker box 120 inside the casing 12. Therefore, the speaker module 100 consisting of the speaker unit 110 and the speaker box 120 is able to generate sound in an amplified manner. In general, an additional antenna module 16 is also set up between the casing 12 and the speaker box 120 for receiving and transmitting signals of the mobile phone 10.
When the mobile phone 10 is reduced in size, the speaker box 120 within the phone must be reduced correspondingly. As a result, the low frequency response of the speaker module 100 will deteriorate. Moreover, the cost of producing a miniaturized speaker unit 110 capable of serving as a loudspeaker, a buzzer and a receiver is especially high. All in all, the cost of producing the mobile phone 10 will be increased.